It has been proposed to place vehicle heating, ventilation and air conditioning (HVAC) systems in the roofs of vehicles, such as tractors. Roof HVAC system designs are described in U.S. Pat. No. 6,780,097, issued 24 Aug. 2004, and in patent application Ser. No. 11/518,050, filed 8 Sep. 2006, both assigned to the assignee of the present application. In order to keep the height of the HVAC system as low as possible, the components of the system must be spread out across much of the roof area. Conditioned air from such an HVAC system blows into the vehicle cab through several vents formed in the roof. Each vent may have adjustable louvers so that airflow through each vent may be controlled individually. Some of the vents may be positioned at a distance from the operator which prevents the operator from comfortably reaching the vents to adjust the louvers. It is desired to provide a mechanism by which an operator can easily adjust air flow through vents which are remote from the operator.